The sick premature infants have high risk for thrombosis. Although therapeutic options include close observation, anticoagulation, thrombolytic therapy, and thrombectomy, guidelines for the management of neonatal arterial and venous thrombosis vary greatly among different centers. The authors report their experience using low molecular weight heparin (enoxaparin), with safe and successful resolution of right atrial thrombus, in an extremely low birth weight infant.